1. Field of the Invention
This invention relates generally to the field of high pressure and increased flow valves and more specifically to an electric tube-type valve, referred to in this specification as an electric coaxial valve, which includes a permanent electromagnet with an armature having three active poles to increase the magnetic force from a permanent magnet, can be operable by pulse current means that provides a brief continuous or pulse electric current for energy efficiency and power versatility, and can be augmented with a balanced spring means for further energy efficiency that works in concert with the magnetic force from the permanent magnet for increased internal force on the tube and increased movement distance of the tube. The electric coaxial valve is dual latching in that it holds its position when not operable by use of the magnetic force from the permanent magnet.
2. Description of Related Art
While the use of tube-type or coaxial valves of various types are well known, to include electromagnetic coaxial valves utilizing a permanent electromagnets having a permanent magnet to magnetically latch the tube and which may be electrically or manually actuated, no such coaxial valve is known to utilize a permanent electromagnet with an armature having three active poles for increase magnetic force, to be pulsed operable by a pulse current means for energy efficiency and power versatility, or to be force augmented by a balanced spring means for increase movement distance and further energy efficiency.
a. Coaxial Valves
In the art of coaxial valves, the highest force for moving the tube is against the pressure of a gas or fluid medium during moving the tube against a valve seat to close flow as the pressure aids in opening the tube to permit flow.
Tube designs and force mechanism have been developed to minimize the force on the tube. In general and without such force reducing means and neglecting seal and other resistances; the pressure P of the medium through the valve times the tube wall cross-sectional area Aw=Th×2πrtube, where Th is the tube wall thickness and rtube is the medium tube radius, determines the force F=P×Aw on the tube; the tube movement distance d times the cross-sectional flow area circumference C=2πr inside the tube equals the cross-sectional flow area Af=πr2=½r×C=d×C through the tube, where r is the radius of the cross-sectional flow area Af—implying that the distance d=½r and Af=4πd2, whereby the force F on the tube times the distance d moved by the tube is equal the energy E=F×d required to move the tube. Noting that the total tube cross-sectional area AT=Af+Aw=πrtube2. That is, the relationships of these parameters give the energy E˜P×Th×Af×(1+Th/r).
Given that the tube wall thickness Th<<r, the energy needed to move the tube E>P×Th×Af. Whereby letting the tube wall thickness Th remain constant with pressure P by assuming that materials can be found to compensate for increase pressure, the relationship of these equations tell us that for increased pressure P or increased flow area Af, the energy E increases.
In typical coaxial valves, the energy E needed to provide the force to move the tube is always taken to be less than or equal to the applied external energy ξ unless some internal energy means is utilized. That is, in coaxial valves increasing the energy E needed to move the tube increases the applied external energy ξ.
b. Permanent Electromagnetic Coaxial Valves
To reduce the external energy required to operate coaxial valves, permanent electromagnetic—electromagnetics containing one or more permanent magnets—have been used. Permanent electromagnetic come in many types. In this specification, permanent electromagnetic referrers to permanent electromagnetics that have a bi-stable magnetic circuit in the poles about two coils, referred to as the electromagnetic means, with a permanent magnet between the coils and the poles, and having the coils wound in a manner to match the applied current to cause the magnetic flux from the permanent magnet to be directed in a bi-directional manner about the electromagnetic means. The permanent magnet providing a dual latching function to latch the tube in the coaxial valve in an open or closed position. Such bi-stable electromagnetic means are typical to the Dual Position Latching Solenoid of U.S. Pat. No. 3,022,450 by Chase in 1962.
Example permanent electromagnetic coaxial valves with a bi-stable electromagnetic means are Jensen (U.S. Pat. No. 5,351,934) and Brudnicki (U.S. Pat. No. 5,529,281), both having two active poles—one moveable and alternating pole on the armature and one stationary and alternating pole attached to the valve housing. In Jensen the permanent magnet does not move with the armature, whereas in Brudnicki the permanent magnet is attached to the armature—moving with it. The electromagnetic principle of motion of the armature is the same, i.e. the magnetic attraction is between the two poles with the two poles alternating sides of the armature, as the armature moves the tube in the coaxial valve to a close or open position.
The difference in the permanent magnet movement is due to the addition of a lever to Brudnicki, which is only a method to manually disengage the armature from a magnetic latched position. The lever has no function to the electrical operability of the valve, but is a means to operate the valve in an electrical energy saving mode by applied mechanical energy from a secondary external energy source. That is, no internal energy is gained by adding the lever, in fact, the lever could increase the electrical energy through added resistance when the armature moves as the lever must also move.
In the art of permanent electromagnetic coaxial valves as those of Jensen and Brudnicki most of the energy needed to move the tube comes from the magnetic force provided by the magnetic flux from the permanent magnet with respect to the pole area on the armature with an external electrical energy source provide to magnet coils to reverse the magnetic flux in the armature. The relationship between the reversal of the magnetic flux and the external electrical energy is a bit complex to discuss here. Although, it can be shown that the external electrical energy increases with the magnetic latching force between the pole on the armature and the stationary pole affixed to the valve housing when abutted.
In the art of magnetic attraction, the force of attraction between two magnetic poles is directly proportional to the product of the strengths of the poles and inversely proportional to the square of the distance between them.
In permanent electromagnets, the strengths of the poles is proportional to the magnetic flux from the permanent magnet at the pole on the armature per the area of the pole on the armature and the distance between poles is the gap distance between the pole on the armature and the stationary pole on the housing. Given the gap distance is the movement distance d of the tube, the magnetic force to move the tube must occur at the initial start of movement of the tube or the gap distance d. Since the magnetic force changes as 1/d2, the magnetic latching force will be much-much greater than the force needed to move theutbe. Therefore, small increases in the force needed to move the tube in permanent electromagnetic coaxial valves will greatly increase the magnetic latching force, which will greatly increase the external electrical energy.
c. Powering Permanent Electromagnet
The external energy for permanent electromagnets is an electrical source, where the external energy ξ=VC and where V is the applied voltage and C is the total charge flow through the electromagnetic means. As the magnetic latching force increases it can be shown that the time tr needed to reverse the magnetic flux also increases. Further, the external energy ξ needs to be applied over the time td the tube moves the distance d. Whereby, the total applied external energy time t=tr+td dictates the electrical power W=ξ/t=V/t=VI, where I is the current to the electromagnetic means.
In the art of continuous electrical power systems, the size of the power system grows with the value of the power VI. Whereby, the size of an electrical power system for permanent electromagnetic coaxial valves using continuous currents even if applied briefly will grow with increased pressure P and flow area Af.